Executive brief
vantage6 is an open-source platform used for privacy-preserving data analysis. A flaw in the multi-factor authentication (MFA) reset process allows an attacker to send an unlimited number of reset emails to a user. This could be used to flood a user's inbox or cause the organization's email server to be flagged as a source of spam, potentially disrupting legitimate communications.
Technical details
A vulnerability classified as Uncontrolled Resource Consumption (CWE-400) exists in vantage6's MFA reset API routes. Prior to version 5.0.0, the application does not implement rate limiting on the number of MFA reset emails that can be requested. An attacker with valid user credentials (password) can repeatedly trigger the API to flood a target's mailbox or exhaust SMTP server resources. While the requirement for a correct password limits the impact, the lack of throttling can lead to service degradation or reputation damage for the sending mail server. The issue is resolved in version 5.0.0.
Affected products
- vantage6 vantage6 < 5.0.0
Timeline
- 2026-06-17: disclosed
- 2026-06-17: advisory
- 2026-06-17: patched: Fixed in version 5.0.0